The atmosphere is an open system not a closed system. Can open flow though system be used to calculate work?
Open systems such as the one shown in the figure below are commonly used to calculate the maximum quantity of work that can be produced when a fluid is moved adiabatically from one reservoir to another; or the minimum quantity of work required to move a fluid adiabatically from one reservoir to another. The equation is a reduced form of the total energy equation which is universally used to calculate work produced or consumed in moving fluid from one location to another. The maximum work is simply equal to the reduction in the enthalpy minus the increase in potential energy. In case of a gas-turbine the change in potential energy is zero and the maximum work is simply the reduction in enthalpy. In the case of hydraulic turbines the change in enthalpy is zero and the maximum work is simply the reduction in potential energy. In the case of the AVE or of atmospheric convection both terms are important, the maximum work is the small difference between two large numbers. Note that the maxim
